Amino borate esters



United States Patent ice 3,303,208 AMINO BORATE ESTERS Chien-wei Liao,Beachwood, Ohio, assignor to The Standgrg Oil Company, Cleveland, Ohio,a corporation of No Drawing. Original application Oct. 18, 1961, Ser.No. 145,988, now Patent No. 3,202,492, dated Aug. 24, 1965. Divided andthis application Dec. 31, 1964, Ser. No. 431,750

4 Claims. (Cl. 260-462) This application is a division of applicationSerial No. 145,988, filed October 18, 1961, now Patent No. 3,202,- 492.

This invention relates to novel metaborate ester-amine reactionproducts, their preparation, and use.

The compounds of this invention are prepared by reacting metaboric acid,or a precursor thereof, with an aliphatic mono-hydroxy alcoholcontaining from 1 to 12 carbon atoms to form a metaborate ester and thenreacting the ester with an aliphatic primary amine containing from 8 to30 carbon atoms.

The compounds of this invention are useful as additives for hydrocarbonfuels of the gasoline boiling range since they are markedly effective insuppressing surface ignition in a spark ignited internal combustionengine. Surface ignition is a phenomenon attributed to combustionchamber deposits which accumulate during the operation of an initiallyclean engine, and is caused principally by such deposits becoming heatedto incandescence within the combustion chambers during engine operation,and igniting the fuel either before or after that portion of the cyclewhere normal spark plug discharge would cause ignition. Surface ignitionmanifests itself in various ways characterized as roughness, rumble,various forms of knocking, and a general lack of smoothness in engineoperation. It has been found that incorporating minor amounts of one ormore of the compounds of this invention in gasoline modifies the actionof the resulting fuel on an engine to provide an overall improvement insmoothness of engine operation.

It is therefore an object of this invention to prepare novel metaborateester-amine reaction products.

It is a further object of this invention to prepare hydrocarbon fuels ofthe gasoline boiling range containing minor amounts of one or more ofthe novel metaborate ester-amine reaction products described herein.

Other objects and advantages will become apparent from the followingdetailed description of the invention.

The novel compounds of this invention may conveniently be prepared by(1) mixing a monohydroxy alcohol and boric oxide in a 2:1 molar ratiotogether with a suitable organic solvent such as benzene, and heating atreflux to azeotropically remove the water of reaction to form a benzenesolution of metaborate ester; and (2) mixing the benzene solution of theester with a primary mono-amine in a 2:1 molar ratio and heating atreflux to remove the alcohol formed in the reaction along with theremaining benzene solvent.

The metaborate ester need not be isolated nor purified since the esterformation is essentially a quantitative reaction, and the solvent doesnot hinder the ester-amine reaction.

To satisfy hydrocarbon solubility and/or stability requirements, thealcohol is preferably an aliphatic monohydroxy alcohol of from 1 to 12carbon atoms, preferably saturated. Straight and branched chain alcoholsare suitable. To satisfy these same requirements, the amine ispreferably a primary aliphatic mono-amine of from 8 to 30 carbon atoms.The hydrocarbon portion of the amine may be straight or branched chain,and commercially available mixtures of amines are also suitable.

3,303,208 Patented Feb. 7, 1967 Example I One mole of diisopropylcarbinol and one-half mole of boric oxide were placed in a flask and tothis was added 250 mls. of benzene. The resulting mixture was heated atreflux until the water of reaction had been removed by azeotropicdistillation, to form a benzene solution of diisopropyl carbinylmetaborate.

Example II To a moiety of the reaction product of Example I containing10.8 grams of diisopropyl carbinyl metaborate was added 2.5 grams (a 2:1molar ratio) of a commercially available mixture of C C branched-chainprimary amines (mol. wt. 191). This mixture was heated at reflux forseveral hours until the alcohol formed in the reaction and the benzenesolvent were removed by distillation.

Example III To a moiety of the reaction product of Example I containing20 grams of diisopropyl carbinyl metaborate was added 6.18 grams (a 2:1molar ratio) of a commercially available mixture of C C primary amines(mol. wt. 263). This mixture was heated at reflux for several hoursuntil the alcohol formed in the reaction and the benzene solvent wereremoved by distillation.

Example IV To a moiety of the reaction product of Example I containing20 grams of diisopropyl carbinyl metaborate was added 7.4 grams (a 2:1molar ratio) of a commercially available mixture of O -C branched-chainprimary amines (mol. wt. 269-311). This mixture was heated at reflux forseveral hours until the alcohol formed in the reaction and the benzenesolvent was removed by distillation.

Specific examples of other alcohols which may be used in the aboveexamples include methanol, isopropanol, 2-ethyl hexanol, hexenol, andmethyl isobutyl carbinol. Specific examples of other amines that may beused are octyl amine, decyl amine, stearyl amine, oleyl amine andhexacosanyl amine.

When used as gasoline adjuvants, the metaborate ester-amine reactionproducts of this invention are effective in concentrations which provideas little as .002 wt. percent boron, based on the weight of gasoline.Generally, concentrations which provide more than 0.1 wt. percent boroncannot be economically justified. The theoretical upper limit foradditive concentration exceeds the practical upper limit dictated byeconomic considerations and is therefore unimportant.

Gasoline base stocks to which these reaction products can be addedinclude any of those conventionally used in preparing a motor fuel for aspark ignited internal combustion engine, such as catalytic distillate,motor polymer, alkylate, catalytic reformate, isomerate, naphthas, etc.The gasoline will preferably contain an anti-knock agent of thetetra-alkyl lead type, such as tetraethyl lead, tetramethyl lead orchemical or physical mixtures thereof, and a scavenger agent such asethylene dichloride and/ or ethylene di-bromide. The amount ofanti-knock agent will usually be at a level of approximately 3 ml./ gal.but may range from /2 ml./ gal. up to 6 ml./gal. The gasoline may alsoinclude other conventional additives such as solvent oils, dyes, and thelike.

The ability of the compounds of this invention to suppress surfaceignition is demonstrated by the following test:

An ASTMCFR single-cylinder engine having a compression ratio adjusted to12:1 was employed in the test. Preparatory to test cycle, the engine wasrun open throt- Vol. Engler Percent saturates The results shown in thetable below are expressed in terms of percentages of the surfaceignition (SI) count for the unmodified base fuel.

SI Rating of Fuel (Per- Concentracent base fuel) tion (wt. AdditivePercent Boron) Total SI Audible SI None 100 100 004 41 0 50. 2 002 53. 117. 3 Example IV 004 38. 3 12. 7

It can be seen from these results that the metaborate ester-aminereaction products of this invention are very effective surface ignitionsuppressants.

It will be understood that various modifications of the presentinvention will occur to those skilled in the art upon reading theforegoing disclosure. It is intended that all such modifications becovered which reasonably fall within the scope of the appended claims.

I claim: 1. A compound selected from the group consisting of compoundsformed by:

(a) reacting metaboric acid or boric oxide with a saturated, aliphatic,monohydroxy alcohol of from 1 to 12 carbon atoms to form a metaborateester;

(b) further reacting the metaborate ester in a 2:1 molar ratio with amember selected from the group consisting of a primary, aliphaticmonoamine of from 8 to 30 carbon atoms, and mixtures of such amines;and,

(c) removing alcohol formed in the reaction.

2. A compound formed by the reaction of claim 1 wherein said alcohol isdiisopropyl carbinol and said member is a mixture of primary, aliphaticmonoamines of from 12 to 14 carbon atoms.

3. A compound formed by the reaction of claim 2 wherein said member is amixture of primary, aliphatic monoamines of from 16 to 18 carbon atoms.

4. A compound formed by the reaction of claim 2 wherein said member is amixture of primary, aliphatic monoamines of from 18 to 21 carbon atoms.

No references cited.

CHARLES B. PARKER, Primary Examiner. D. R. PHILLIPS, Assistant Examiner.

1. A COMPOUND SELECED FROM THE GROUP CONSISTING OF COMPOUNDS FORMED BY:(A) REACTING METAORIC ACID OR BORIC OXIDE WITH A SATURATED, ALIPHATIC,MONOHYDROXY ALCOHOL OF FROM 1 TO 12 CARBON ATOMS TO FORM A METABORATEESTER; (B) FURTHER REACTING THE METABORATE ESTER IN A 2:1 MOLAR RATIONWITH A MEMABER SELECTED FROM THE GROUP CONSISTING OF A PRIMARY,ALIPHATIC MONOAMINE OF FROM 8 TO 30 CARBON ATOMS, AND MIXTURES OF SUCHAMINES; AND, (C) REMOVING ALCOHOL FORMED IN THE REACTION.